?????λ??Indoor Location?????????????GPS?????????????????????????????????????????????????????????Wi-Fi??λ??Wi-Fi Location???????о?????????????????????????4G????????????????????????

??????????????????????????????????????ultrawide band?????beacon??????????????????????????????????????????????????????????????г?????ABI Research???????2021????????5000???????????????????????????г?????????弴???λ?????????????г?????????150???????

???????????????Wi-Fi?????WFA?????г????????????????????2020???????λ????mobile location-based services???г?????350??????????????????Wi-Fi??λ??????????25?????????

?????г?????ж???г????????????????????????????WFA?????????????Broadcom??????????Intel??????????Marvell???????????Mediatek?????????Qualcomm?????????Realtek??????????????νWi-Fi??λо???

?????????????????????????????????????signal timestamps?????????????????????????λ???????????IEEE 802.11-2016???????????Fine Timing Measurement????Э?顣

?????Wi-Fi???????802.11az????????????У?????????????????????????????????????????????????????????????????????????????????????????????о??????????????????????????????????

Wi-Fi??λ??????????????????????????round-trip time??????

?????Wi-Fi??λ????????????????????????????в?????°?о?????????????????????????????????????????????????ó???????????????書???

WFA?????????Kevin Robinson???????????????????Wi-Fi??????????????????????λ?????????á??????????????????е????????????????????????????λ????????????????????????Χ??????????????????????????????

????Wi-Fi??????????????????????????????????????????????λ????????????????????????????Wi-Fi??????????????Wi-Fi???????????????????λ?????????????????????????2??????????????е???е???????????????侫??????????

?滮???????????????????????????????????????60Hz Wi-Fi????????????????????????????????????????????????????????????Google??????????????????Э?????????????

LTE????λ????

??????PoLTE???????????????????Wi-Fi??????λ??????????ù????????????д??????????????侫??????2~6?????PoLTE????????????ж??????MWC 2017????????????“LTE??λ??position over LTE??”?????????GPS???????LTE???????????????λ?????

PoLTE?????????????????λ?????????????LTE?????е?ο???????????????λ????????ù??????????????????????н??????????????????/??λ??????

???????????У?PoLTE??г?Russ Markhovsky?????“??????????????????????????????Wi-Fi????????GPS??????”???ù????????John Dow????????????豸??????ù???????????????????????????????????λ????????

Dow?????“???????????ж??????????????????????????LTEо?????????????????????????豸???????????????2018????????????”

???????Wi-Fi?????????????????????????????LTE??λ?????????????????????????С?????????￥?????????“?????????￥???е?????У?????????95%??????3?????????????68%??????1??????????ó?????н????????LTE???????LTE???????”

??PoLTE??Intel??????У?LTE?????????2~6?????????

Wi-Fi??LTE????λ?????г????????????缼???????????????????????????????λ????e????????????????????????????顣??????????λ???????????????????t?????λ????????????????й????????????????????????Amazon????????????????

?????????

??2014-2018??????????λ?????г???